Display device

ABSTRACT

According to one embodiment, provided is a liquid crystal display device with a reduced size and little restriction for incorporation into other devices. The liquid crystal display device includes an array substrate that includes multiple thin film transistors for pixel driving. The liquid crystal display device also includes a counter substrate disposed in a manner opposed to the array substrate. The liquid crystal display device further includes an FPC arranged to transmit an external signal for driving of the thin film transistors. One of the array substrate and the counter substrate has an outline larger than that of the other, disposed on the display side, and includes a connecting portion at a position not opposed to the other on the side opposite to the display side. At least one end portion of the FPC is connected to the connecting portion, while the other end portion extends inward.

INCORPORATION BY REFERENCE

The present invention claims priority under 35 U.S.C. §119 to JapanesePatent Application No. 2014-122466 filed on Jun. 13, 2014. The contentof the application is incorporated herein by reference in its entirety.

FIELD

An embodiment of the present invention relates to a display device inwhich a signal transmission member arranged to transmit an externalsignal for driving of a drive element is connected to a substrate.

BACKGROUND

As displays of mobile applications typified by, for example,smartphones, large-screen liquid crystal display devices have recentlybeen spreading rapidly. Such displays employed in mobile devices haveshown a trend toward large-screen and high-definition display in lightof capacity of displayed information and screen visibility.

However, such mobile devices, which are mainly in the manner of beingheld and operated in an operator' s hand, preferably have as small asize of the device itself as possible, resulting in that the peripheralarea other than the display area (display surface) is required to havean area reduced as small as possible.

To meet this requirement, low-temperature polysilicon (LTPS) liquidcrystal display devices in which a display area driving circuit isincorporated in the substrate have recently been increasingly employed,in which the peripheral area other than the display area has asignificantly reduced area compared to amorphous silicon (a-Si) liquidcrystal display devices that require many driving ICs to be providedoutside the glass substrate, composing the mainstream of current mobiledevice displays.

On the other hand, display devices even using low-temperaturepolysilicon need input of a driving signal, which in turn requires anadditional space for folding of a flexible printed circuit (FPC) boardconnected to a connecting portion and arranged to supply, for example,an external signal and a power supply voltage, in the connecting portionoften set mainly closer to the lower side of the quadrilateral displayarea. That is, the flexible printed circuit board, which is used forconnection with an interconnection formed on the array substrate, isusually required to be folded by 180 degrees on the back side in orderto be connected with an external signal source existing on the back sideof the substrate so as not to impact the display, resulting in anincrease in the external signal interfacing area by the space requiredfor folding.

In addition, the connecting portion of the flexible printed circuitboard is exposed on the display side and it is therefore necessary toavoid interference between a protective glass and/or a touch panelglass, which are needed for incorporation into actual mobile applicationsets such as smartphones, and the connecting portion, placing manyrestrictions on, for example, the position, thickness, and design of theflexible printed circuit board.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional view partially showing a display deviceaccording to a first embodiment.

FIG. 2 is an illustrative view partially showing the display device.

FIG. 3 is a cross-sectional view partially showing a display deviceaccording to a second embodiment.

FIG. 4 is a cross-sectional view partially showing a display deviceaccording to a third embodiment.

FIG. 5 is a cross- sectional view partially showing a display deviceaccording to a fourth embodiment.

FIG. 6 is a cross-sectional view partially showing a display deviceaccording to a fifth embodiment.

FIG. 7 is a cross-sectional view partially showing a display deviceaccording to a sixth embodiment.

FIG. 8A and FIG. 8B show a display device according to a seventhembodiment, FIG. 8A being a plan view on the display side and FIG. 8Bbeing a plan view on the side opposite to the display side.

FIG. 9 is a cross-sectional view partially showing a display deviceaccording to a conventional example.

DETAILED DESCRIPTION

Embodiments provide a display device including a first substrate thatincludes multiple drive elements for pixel driving. The display devicealso includes a second substrate disposed in a manner opposed to thefirst substrate. The display device further includes a signaltransmission member arranged to transmit an external signal for drivingof the drive elements. One of the first substrate and the secondsubstrate has an outline larger than that of the other, is disposed onthe display side, and includes a connecting portion at a position notopposed to the other on the side opposite to the display side. At leastone end portion of the signal transmission member is connected to theconnecting portion, while the other end portion extends inward.

An arrangement according to a first embodiment will hereinafter bedescribed with reference to FIGS. 1 and 2.

In FIGS. 1 and 2, the reference numeral 11 denotes a liquid crystaldisplay device serving as a display device. The liquid crystal displaydevice 11 is used in various types of terminals such as cell-phones,smartphones, portable game consoles, personal computers, tablet PCs, andin-vehicle navigation display devices. The liquid crystal display device11 then includes an LCD panel 12 being a display device main body and abacklight 13 being a planar light source device disposed on the backside of the LCD panel 12 and is disposed inside a chassis frame being aset chassis not shown. In addition, the following description is basedon the definition that the display side (upper side in FIG. 1) of theLCD panel 12 is the front side, while the opposite side (lower side inFIG. 1) is the back side, that is, the rear side.

The LCD panel 12 is of a transmissive type in which planar light fromthe backlight 13 is transmitted to display an image, semi-transmissivetype including a transmissive portion through which planar light fromthe backlight 13 is transmitted and a reflective portion at whichincident light from the front is reflected, or a reflection/transmissioncombined type, and of an active matrix type. The LCD panel 12 thenincludes a quadrilateral array substrate 21 serving as a first substrateand a quadrilateral counter substrate 22 serving as a second substratethat are disposed in a mutually opposed manner with the array substrate21 positioned in front and with a predetermined gap (cell gap)therebetween and, between the substrates 21 and 22, a liquid crystallayer 23 being an optical modulation layer and a spacer not shownarranged to maintain the gap between the substrates 21 and 22 areprovided and the substrates 21 and 22 are bonded to each other via asealing portion 24, and further polarizing plates 25 and 26 areattached, respectively, to the front side of the array substrate 21 andthe rear side of the counter substrate 22. Secondary pixels P for imagedisplaying are arranged in a matrix in the vertical (V) direction andthe horizontal (H) direction to form a quadrilateral active area, thatis, a display area 27 on which an image can be displayed. Thequadrilateral frame-shaped portion of the entire liquid crystal displaydevice 11 outside the display area 27 is a frame portion 28 being aperipheral area. In addition, on the display side of the LCD panel 12, afunctional member such as a protective glass being a protecting memberor a touch panel for touch input detection is bonded, though not shown.

The array substrate 21 has a transmissive glass substrate 31 being afirst insulating substrate and, on a principal surface of the glasssubstrate 31 closer to the liquid crystal layer 23, a scanning line(gate interconnection) 32 and a signal line (source interconnection) 33being multiple interconnections formed of a conductor such as a metalmember in a thin film are arranged in a mutually insulated and grid-like manner approximately orthogonal to each other in a plan view. Atthe intersection between the scanning line 32 and the signal line 33, athin film transistor (TFT) 34 for pixel driving being a drive element(switching element) is disposed, on which an orientation film not shownfor orientation of liquid crystal molecules being display elements ofthe liquid crystal layer 23 is provided. In this embodiment, the arraysubstrate 21 has an outline larger than that of the counter substrate 22and, on the glass substrate 31, a non-opposed portion 35 is formed notopposed to the counter substrate 22, that is, provided in a mannerprotruding (extending) outward from an outer rim (outer edge portion) ofthe counter substrate 22.

The scanning line 32 and the signal line 33 are formed in the sameprocess as part of the thin film transistor 34 and electricallyconnected with a connecting portion 37 including many pad electrodes andthe like, one end portion of which is extracted onto the non-opposedportion 35. Accordingly, the connecting portion 37 is not opposed to thecounter substrate 22 and positioned on the back side (rear side), whichis opposite to the display side of the array substrate 21 (glasssubstrate 31). A flexible printed circuit board 41 (hereinafterabbreviated as FPC 41) serving as a signal transmission member is thenelectrically and mechanically connected to the connecting portion 37 viaa thin film conductive member 42 such as an anisotropic conductive film(ACF) and, on the FPC 41, a drive circuit (driver) 43 for driving ofeach thin film transistor 34 (secondary pixel P) is mounted.

The FPC 41, which is also referred to as, for example, flexible tape, isformed of synthetic resin such as polyimide in a sheet thinner than thearray substrate 21 and the counter substrate 22 and has flexibility. Oneend portion 41 a of the FPC 41 is electrically and mechanicallyconnected with the connecting portion 37 in the non-opposed portion 35,while the other end extends inward with respect to the outer rim (outeredge portion) of the array substrate 21 and is bent toward the rear sideto be laid and fixed using, for example, a double-sided tape not shownonto the back side of the backlight 13 as well as electrically connectedto an external signal source and a voltage source not shown.Accordingly, the portion of the non-opposed portion 35 of the arraysubstrate 21 protruding outward from the counter substrate 22 andincluding the position at which the one end portion 41 a of the FPC 41and the connecting portion 37 are connected is an external signalinterfacing area A.

The drive circuit 43 is electrically and mechanically connected to theother end side of the FPC 41, that is, a position spaced from the oneend portion 41 a via a thin film conductive member 45 such as ananisotropic conductive film (ACF).

Accordingly, the drive circuit 43 is electrically connected with thescanning line 32 and the signal line 33 via the FPC 41 and theconnecting portion 37 as well as electrically connected to the externalsignal source and the voltage source via the FPC 41.

Each thin film transistor 34 is electrically connected, via its gateelectrode being a control electrode, to the scanning line 32,electrically connected, via its source electrode being an inputelectrode, to the signal line 33, and electrically connected, via itsdrain electrode being an output electrode, to a transparent pixelelectrode 47 forming each secondary pixel P. Each thin film transistor34 can then undergo switching control when a signal from the drivecircuit 43 is applied to the gate electrode via the scanning line 32 andcan independently drive on/off each secondary pixel P by applying avoltage to the pixel electrode 47 correspondingly to a signal input fromthe drive circuit 43 via the signal line 33.

On the other hand, the counter substrate 22 includes, for example, atransmissive glass substrate 51 being a second insulating substrate, acounter electrode 52 being a common electrode formed on the glasssubstrate 51, and a color filter layer and an orientation film notshown. The counter substrate 22 is thus basically formed with no metalinterconnection or the like. In addition, the counter electrode 52 maybe formed on the array substrate 21 depending on the mode of the liquidcrystal layer 23. The color filter layer may also be formed on the arraysubstrate 21.

The liquid crystal layer 23 can employ various types of modes such as TNmode, STN mode, VA (MVA) mode, and IPS mode.

The sealing portion 24 is provided to bond the substrates 21 and 22 toeach other and thereby seal the liquid crystal layer 23 between thesubstrates 21 and 22 and is formed through curing of, for example,ultraviolet (UV) curable resin or thermosetting resin in an annularshape surrounding the display area 27 (liquid crystal layer 23).

The polarizing plates 25 and 26 are optical members formed in a sheetand arranged to selectively transmit or block a predeterminedpolarization component according to the mode of the liquid crystal layer23.

The backlight 13 includes a light source not shown, a quadrilateralplate-like light guide plate 56 being a light guide body arranged toconvert light from the light source into planar light, multiple opticalsheets not shown disposed in a laminated manner in front of the lightguide plate 56 to reduce light distribution unevenness, and a reflectingsheet not shown disposed in a laminated manner in the rear of the lightguide plate 56, the backlight 13 arranged to irradiate the rear side ofthe LCD panel 12 with planar light.

The light source employs, for example, a light emitting diode (LED) andis disposed in a manner opposed to one end of the light guide plate 56.

The light guide plate 56 is disposed in an opposed manner in the rear ofthe LCD panel 12. One end of the light guide plate 56 opposed to thelight source is an incident surface for incidence of light therethroughfrom the light source. The front principal surface (one principalsurface) of the light guide plate 56, which is opposed to the rear sideof the LCD panel 12, is an outgoing surface through which light goesout, and the rear principal surface (the other principal surface), whichis opposite to the outgoing surface, is a refractive surface at whichlight is reflected (refracted). The outer edge portion of the lightguide plate 56 then extends outside of the outer edge portions of thedisplay area 27 and the LCD panel 12 so that at least the areacorresponding to the entire display area 27 of the LCD panel 12 can beirradiated with planar light, whereby the outgoing surface (and therefractive surface) has an area larger than that of the display area 27and the LCD panel 12.

Next will be described a manufacturing method according to the firstembodiment.

First, an array substrate 21 and a counter substrate 22 are manufacturedseparately.

The array substrate 21 is formed with a scanning line 32, a signal line33, a thin film transistor 34, and a connecting portion 37 throughrepeated film formation and patterning on a glass substrate 31, and anorientation film is formed in a manner covering the scanning line 32,the signal line 33, the thin film transistor 34, and the connectingportion 37.

Similarly, the counter substrate 22 is formed with a counter electrode52 and a color filter layer through repeated film formation andpatterning on a glass substrate 51, and an orientation film is formed ina manner covering the counter electrode 52 and the color filter layer.

Next, the array substrate 21 and the counter substrate 22 are bonded toeach other through curing of a fluidic sealing portion 24 applied, andthus a liquid crystal layer 23 is sealed between the substrates 21 and22. In addition, any procedure such as a one-drop-fill (ODF) method or avacuum injection method can be used for filling of the liquid crystallayer 23.

Thereafter, one end portion 41 a of an FPC 41 on which a drive circuit43 has preliminarily been mounted via a conductive member 45 iselectrically and mechanically connected by, for example,thermocompression bonding to the connecting portion 37 of the arraysubstrate 21 via a conductive member 42. Upon this, the FPC 41 isconnected to the connecting portion 37 such that the other end overlapsthe central portion of the array substrate 21 and the one end portion 41a does not protrude from the outer edge portion of the array substrate21 (glass substrate 31).

Further, polarizing plates 25 and 26 are bonded, respectively, to thearray substrate 21 and the counter substrate 22 to complete an LCD panel12.

The LCD panel 12 is then laid on a separately assembled backlight 13with the counter substrate 22 side therebetween, and the other end sideof the FPC 41 is bent and fixed to the back side of the LCD panel 12 andthe like using, for example, a double-sided tape.

Thereafter, a functional member such as a protective glass or a touchpanel is appropriately applied to the display side of the LCD panel 12,on the array substrate 21 (polarizing plate 25) in this embodiment,using, for example, transparent synthetic resin or a double-sided tapeto be housed in a chassis frame.

An external signal source or a voltage source is appropriately andelectrically connected to the other end side of the FPC 41.

In the thus completed liquid crystal display device 11, liquid crystalmolecules are driven at the position of each secondary pixel P by thethin film transistor 34 driven according to a signal from, for example,the external signal source so that the amount of light transmission fromthe backlight 13 through each secondary pixel P is controlled and thelight through each secondary pixel P colored by the color filter layercauses an image to be displayed in the display area 27, which image isthen recognized by user' s eyes E.

As described heretofore, in accordance with the first embodiment, sincethe array substrate 21 with the outline larger than that of the countersubstrate 22 is disposed on the display side and the one end portion 41a of the FPC 41 is connected to the connecting portion 37, which isprovided in the non-opposed portion 35 of the array substrate 21 notopposed to the counter substrate 22, with the other end extending inwardof the array substrate 21, it is possible to easily form a structure inwhich the FPC 41 does not protrude outward from the LCD panel 12 (arraysubstrate 21) only by changing the direction of connection of the oneend portion 41 a of the FPC 41 to the connecting portion 37 withoutsignificantly changing the design of the array substrate 21 and thecounter substrate 22 than before.

In addition, since the connecting portion 37 has an interconnectionstructure integrated with the scanning line 32 and the signal line 33,which are formed in the same process as part (gate electrode, sourceelectrode, and drain electrode) of the thin film transistor 34, noadditional process of forming the connecting portion 37 is needed,resulting in a further improvement in productivity.

Next will be described a second embodiment with reference to FIG. 3. Inaddition, arrangements and operations identical to those in the firstembodiment are designated by the same reference numerals to omitdescription thereof.

In the second embodiment, the first embodiment is modified such that thecounter substrate 22 has an outline larger than that of the arraysubstrate 21 and is disposed on the display side, while the arraysubstrate 21 is disposed on the back side.

That is, the non-opposed portion 35 is a portion of the countersubstrate 22 (glass substrate 51) not opposed to the array substrate 21and provided in a manner protruding (extending) outward from an outerrim (outer edge portion) of the array substrate 21, and the connectingportion 37 is provided in the non-opposed portion 35. Accordingly, theconnecting portion 37 is positioned in the frame portion 28 outside thedisplay area 27, and the portion of the non-opposed portion 35 of thecounter substrate 22 protruding outward from the array substrate 21 andincluding the position at which the one end portion 41 a of the FPC 41and the connecting portion 37 are connected is an external signalinterfacing area A.

Also, the scanning line 32 and the signal line 33 of the array substrate21 are electrically connected with the connecting portion 37 of thecounter substrate 22 directly through many signal interfacing units 61introduced in the sealing portion 24 or indirectly through a signal linedriver circuit and/or a scanning line driver circuit formed on the arraysubstrate 21.

The signal interfacing units 61 each have a spherical shape in which aconductive layer 61 b of, for example, gold (Au) is evaporativelydeposited on the surface of a spherical body (pearl) 61 a being asynthetic resin support, and the portion of the sealing portion 24 inwhich the signal interfacing units 61 are introduced is an anisotropicconductive member having conductivity only in the front-back direction.The signal interfacing units 61 are each formed to have a sizeapproximately equal to that of, for example, the spacer arranged tomaintain the gap between the substrates 21 and 22, and sandwiched in thefront-back direction between the array substrate 21 and the countersubstrate 22 to maintain the gap as well as arranged to electrically andmechanically connect the scanning line 32 and the signal line 33 withthe connecting portion 37.

During manufacture of the liquid crystal display device (LCD panel 12),many signal interfacing units 61 are introduced into the sealing portion24 at the site of connection of the scanning line 32 and the signal line33 with the connecting portion 37 when the array substrate 21 and thecounter substrate 22 are bonded, whereby an external force is applied tobond the array substrate 21 and the counter substrate 22 and slightlypress and deform the sealing portion 24, and the sealing portion 24 iscaused to cure with the scanning line 32 and the signal line 33 beingelectrically connected, in the front-back direction, with the connectingportion 37 via the signal interfacing units 61.

Since the counter substrate 22 with the outline larger than that of thearray substrate 21 is thus disposed on the display side and theconnecting portion 37, which is provided in the non-opposed portion 35of the counter substrate 22 not opposed to the array substrate 21, iselectrically connected with the scanning line 32 and the signal line 33of the array substrate 21 via the signal interfacing units 61, and theone end portion 41 a of the FPC 41 is connected to the connectingportion 37 with the other end extending inward of the counter substrate22, thereby the counter substrate 22 can be positioned on the displayside, which basically has no metal interconnection or the like in thedisplay area 27 that would reflect light from the backlight 13 throughthe liquid crystal layer 23 of the LCD panel 12, whereby it is possibleto eliminate the influence of unnecessary reflection at such aninterconnection, resulting in a further improvement in display quality.

Next will be described a third embodiment with reference to FIG. 4. Inaddition, arrangements and operations identical to those in theabove-described embodiments are designated by the same referencenumerals to omit description thereof.

In the third embodiment, the second embodiment is modified such that theconnecting portion 37 extends outward of the array substrate 21 togetherwith the sealing portion 24 and is fixed at the position of thenon-opposed portion 35 of the counter substrate 22 via the sealingportion 24 in an exposed manner.

The connecting portion 37 is formed by forming a film on, for example,the glass substrate 31 of the array substrate 21 via a predeterminedpeeling layer, bonding the array substrate 21 and the counter substrate22 via the sealing portion 24 in a manner covering the connectingportion 37, and then partially peeling off the glass substrate 31.

Since the connecting portion 37 once formed on the array substrate 21 isthus fixed to the non-opposed portion 35 of the counter substrate 22 viathe sealing portion 24 by peeling off the glass substrate 31 of thearray substrate 21, no arrangement is needed for preliminarily providinga connecting portion on the counter substrate 22 and electricallyconnecting with the scanning line 32 and the signal line 33 on the arraysubstrate 21, whereby it is possible to manufacture the liquid crystaldisplay device 11 more easily.

Next will be described a fourth embodiment with reference to FIG. 5. Inaddition, arrangements and operations identical to those in theabove-described embodiments are designated by the same referencenumerals to omit description thereof.

In the fourth embodiment, the second embodiment is modified such thatthe FPC 41 is electrically and mechanically connected with theconnecting portion 37 on the counter substrate 22 via a printed circuitboard 63 (hereinafter abbreviated as PCB 63) serving as a connectingmember.

The PCB 63 is, for example, a multilayer substrate and includes a viahole 63 a for electrical interlayer connection along the normaldirection (front-back direction) of the substrates 21 and 22 being thethickness direction. The PCB 63 is also formed to have a thicknessapproximately equal to the total thickness of the array substrate 21 andthe backlight 13, the front side thereof electrically and mechanicallyconnected with the connecting portion 37 via the conductive member 42 ata position close to the array substrate 21 (glass substrate 31), whilethe rear side thereof electrically and mechanically connected to the oneend portion 41 a of the FPC 41 on the surface opposite to the drivecircuit 43. The PCB thus electrically connects the connecting portion 37(scanning line 32 and signal line 33) and the drive circuit 43 via thevia hole 63 a. The PCB 63 is also formed to be elongated along thenon-opposed portion 35.

Since the PCB 63 for signal transmission between the connecting portion37 and the FPC 41 is provided between the connecting portion 37 and theone end portion 41 a of the FPC 41 along the normal direction of thesubstrates 21 and 22, the FPC 41 can be disposed in an approximatelyflat manner, so that no space is needed for bending of the FPC 41 as inthe case where the one end portion 41 a of the FPC 41 is connecteddirectly to the counter substrate 22, whereby it is possible to reducethe size of the connecting portion 37 (non-opposed portion 35).

In addition, the liquid crystal display device 11, which is of atransmissive, semi-transmissive, or reflection/transmission combinedtype in the first to fourth embodiments, may be of a reflective typeincluding no backlight 13 with the same configuration.

Next will be described a fifth embodiment with reference to FIG. 6. Inaddition, arrangements and operations identical to those in theabove-described embodiments are designated by the same referencenumerals to omit description thereof.

In the fifth embodiment, the fourth embodiment is modified such that alight source 65 for the backlight 13 is mounted lateral to the PCB 63.

The light source 65 is, for example, an LED and disposed on a sidesurface of the PCB 63 in a manner opposed to the incident surface of thelight guide plate 56. The light source 65 is electrically connected withan interconnection inside the PCB 63 and arranged to be turn-oncontrolled by an external turn-on circuit not shown mounted on the PCB63 or the FPC 41 or electrically connected with the FPC 41.

Since the light source 65 is thus disposed on the PCB 63, the number ofcomponents can be reduced compared to the case where a light source, acontrol circuit for turning on the light source, etc., are configuredseparately, resulting in a further reduction in production cost.

Next will be described a sixth embodiment with reference to FIG. 7. Inaddition, arrangements and operations identical to those in theabove-described embodiments are designated by the same referencenumerals to omit description thereof.

In the sixth embodiment, the fifth embodiment is modified such that thelight source 65 is mounted on the surface of the FPC 41 opposite to thedrive circuit 43. In this state, the FPC 41 is disposed in a manneropposed to the incident surface of the light guide plate 56. The lightsource 65 is also arranged to be turn-on controlled by an externalturn-on circuit not shown mounted on the FPC 41 or electricallyconnected with the FPC 41.

Thus being disposed on the FPC 41, the light source 65 can be disposedeasily even if it may not be easy to dispose the light source 65integrally on, for example, the PCB 63, whereby the number of componentscan be reduced compared to the case where a light source, a controlcircuit for turning on the light source, etc., are configuredseparately, resulting in a further reduction in production cost.

In addition, the structure in which the light source 65 is mounted onthe FPC 41 as in the sixth embodiment can also be applied to the firstto fourth embodiments.

Next will be described a seventh embodiment with reference to FIG. 8Aand FIG. 8B. In addition, arrangements and operations identical to thosein the above-described embodiments are designated by the same referencenumerals to omit description thereof.

The liquid crystal display device 11 according to the seventh embodimenthas a circular shape having a circular display area 27 in which thearray substrate 21 (glass substrate 31) and the counter substrate 22(glass substrate 51) of the above-described embodiments are formed in acircular shape in a plan view. Although this embodiment is describedbased on the arrangement that the array substrate 21 is disposed on therear side (back side), while the counter substrate 22 is disposed on thefront side (display side), the array substrate 21 may be disposed on thefront side (display side), while the counter substrate 22 maybe disposedon the rear side (back side) as in the first embodiment.

On the array substrate 21, multiple driver circuit block portions 67 fordriving of each thin film transistor 34 (each secondary pixel P) aredisposed in an annular frame portion 28 positioned on the periphery ofthe display area 27. The driver circuit block portions 67 are disposedin, for example, circumferentially and approximately quartered areas ofthe array substrate 21 (glass substrate 31) such that scanning linedriver circuit block portions 67 a for switching control of each thinfilm transistor 34 via the scanning line 32 and signal line drivercircuit block portions 67 b for sending an image signal to each thinfilm transistor 34 via the signal line 33 are arranged alternately inthe circumferential direction.

The scanning line driver circuit block portions 67 a are each arrangedhorizontally (H) along the outer edge of the display area 27, while thesignal line driver circuit block portions 67 b are each arrangedvertically (V) along the outer edge of the display area 27.

Also, the outline (outside diameter) of the array substrate 21 (glasssubstrate 31) positioned on the rear side is set smaller than that ofthe counter substrate 22 (glass substrate 51) positioned on the displayside. Further, the array substrate 21 and the counter substrate 22 arearranged approximately concentrically with each other. Accordingly, anon-opposed portion 35 not opposed to the array substrate 21 is formedin the outer edge portion of the counter substrate 22 and, in thenon-opposed portion 35, a connecting portion 37 is formed, and the bothend portions of the FPC 41 are electrically and mechanically connectedto the connecting portion 37, as is the case in the above-describedembodiments, and the connecting portion 37 is arranged in the radialdirection such that the portion between the both end portions extendsinward (toward the center).

The FPC 41 is formed in an hourglass shape in which the both endportions are each formed in an arc shape along, for example, the outeredge portion of the counter substrate 22 (glass substrate 51) and thewidth becomes narrowed gradually toward the central portion. The bothend portions are electrically and mechanically connected with theconnecting portion 37 at the position on the back side corresponding tothe signal line driver circuit block portions 67 b. On the FPC 41, drivecircuits 43 and 43 are also mounted and, in the central portion, forexample, a connector portion 69 is mounted to be electrically connectedwith, for example, an external signal source and a voltage source. Thedriver circuit block portions 67 are then electrically connected withthe drive circuits 43 and 43 and the connector portion 69 via the FPC 41so that a signal and a voltage are transmitted from the external signalsource and the voltage source to the driver circuit block portions 67.

Also in the circular liquid crystal display device 11, since the endportions of the FPC 41 are thus connected to the connecting portion 37formed at the position of the counter substrate 22 not opposed to thearray substrate 21 and opposite to the display side, no linear portioncould occur as in, for example, the conventional case where the FPC isconnected on the display side and folded to the opposite side (asindicated by the imaginary line L), whereby the outline (outsidediameter) can be reduced significantly.

In addition, in the seventh embodiment, the array substrate 21 and thecounter substrate 22 may each have a polygonal shape with five or morecorners to exhibit the same operational effects.

In accordance with at least one of the above-described embodiments, inthe liquid crystal display device 11 having a cell structure in whichthe substrates 21 and 22 are opposed and bonded to each other, the arraysubstrate 21 or the counter substrate 22 positioned on the display sidehas an outline larger than that of the counter substrate 22 or the arraysubstrate 21, and at least one end portion of the FPC 41 is connected tothe connecting portion 37, which is provided in the non-opposed portion35 exposed in a view on the side opposite to the display side, such thatthe other end portion side extends inward, that is, toward the side notto protrude from the outer rim of the liquid crystal display device 11(LCD panel 12 (substrates 21 and 22)). As a result, compared to thestructure in which the FPC 41 is folded on the back side of the arraysubstrate 21 and laid on the backlight 13 as in the conventional exampleshown in FIG. 9, the folded portion of the FPC 41 protruding outwardfrom the array substrate 21 (or the counter substrate 22) can be removedand thereby no additional space is required for the FPC 41, whereby thearea of the connecting portion 37 and the non-opposed portion 35, thatis, the external signal interfacing area A can be reduced significantlyand the structure of the liquid crystal display device 11 on the displayside becomes flat, that is, planar and uniform, which places norestriction on the application of a functional member such as aprotective glass or a touch panel for incorporation into other devices,that is, other device sets, resulting in a significant improvement inthe degree of freedom of design. It is therefore possible for the liquidcrystal display device 11 to have a smaller size and better design.

While a certain embodiment of the present invention has heretofore beendescribed, the embodiment has been presented by way of example only andis not intended to limit the scope of the invention. For example, thedisplay device may be an organic EL display device and the like, inplace of the liquid crystal display device. Indeed, the novel embodimentdescribed herein may be embodied in a variety of other forms;furthermore, various omissions, substitutions, and variations may bemade without departing from the spirit of the invention. The appendedclaims and their equivalents are intended to cover the embodiment andits modifications as would fall within the scope and spirit of theinvention.

What is claimed is:
 1. A display device comprising: a first substrateincluding a plurality of drive elements for pixel driving; a secondsubstrate disposed in a manner opposed to the first substrate; and asignal transmission member arranged to transmit an external signal fordriving of the drive elements, wherein one of the first substrate andthe second substrate has an outline larger than that of the other,disposed on the display side, and includes a connecting portion at aposition not opposed to the other on the side opposite to the displayside, and wherein at least one end portion of the signal transmissionmember is connected to the connecting portion, while the other endportion side extends inward.
 2. The display device according to claim 1,wherein the first substrate has an outline larger than that of thesecond substrate and is disposed on the display side.
 3. The displaydevice according to claim 2, wherein the connecting portion isconstituted by an interconnection structure formed in the same processas part of the drive elements.
 4. The display device according to claim1, wherein the second substrate has an outline larger than that of thefirst substrate and is disposed on the display side, the display devicefurther comprising a signal interfacing unit provided between the firstsubstrate and the second substrate to transmit a signal between thefirst substrate and the second substrate.
 5. The display deviceaccording to claim 1, further comprising a connecting member providedbetween the connecting portion and one end side of the signaltransmission member to transmit a signal between the connecting portionand the signal transmission member along a normal direction with respectto one of the first substrate and the second substrate.
 6. The displaydevice according to claim 5, wherein the connecting member is a printedcircuit board.
 7. The display device according to claim 5, arranged atleast partially to transmissively display an image thereon and furthercomprising a backlight having a light source disposed on the connectingmember and a light guide body arranged to convert light from the lightsource into planar light and make the planar light incident into theother of the first substrate and the second substrate.
 8. The displaydevice according to claim 1, arranged at least partially totransmissively display an image thereon and further comprising abacklight having a light source disposed on the signal transmissionmember and a light guide body arranged to convert light from the lightsource into planar light and make the planar light incident into theother of the first substrate and the second substrate.
 9. The displaydevice according to claim 1, wherein the drive elements are thin filmtransistors.
 10. The display device according to claim 1, wherein thesignal transmission member is a flexible printed circuit board.